Method for molding a one-piece molded end closure

ABSTRACT

A one-piece molded end closure has a pull ring spaced from a main panel having an annular flange extending therefrom. When the end closure is frangible through having score lines formed in the main panel, the pull ring is connected by a tenon adjacent a score point, which is the junction of two score lines and inside of the inner diameter of the pull ring, so that pulling on the pull ring, which is substantially parallel to the main panel, starts rupturing of the two score lines. The end closure also may be a plug type having a friction fit within a container whereby there are no score lines; the pull ring is still used to remove the end closure from the open end of the container. The method and apparatus for molding enable production of the end closure as one piece without any tearing of the pull ring or rupturing of the score lines when the end closure is removed from the molding apparatus. The main panel may be formed with a single continuous score line and the pull ring not at the center of the main panel. The end closure also may be formed integral with a cylindrical side wall of the container rather than having the end closure molded separately and then being sealed to an open end of a container.

This is a division of application Ser. No. 062,784, filed Jun. 15, 1987now U.S. Pat. No. 4,830,214. Application Ser. No. 062,784 is acontinuation in part of U.S. application Ser. No. 796,705, filed Nov.12, 1985, now abandoned and of U.S. application Ser. No. 863,238, filedMay 14, 1986 now abandoned, a division of U.S. application Ser. No.796,705 now abandoned.

This invention relates to a one-piece molded end closure and, moreparticularly, to a one-piece molded end closure having a pull ringspecifically located relative to score lines in a main panel of the endclosure when the end closure has score lines, a one-piece molded endclosure integral with a wall of a container, and a method and apparatusfor molding the end closure and the end closure integral with a wall ofa container with the end closure having the pull ring in spaced relationto the main panel of the end closure.

An end closure is used to close an open end of a container such as acan, for example. The end closure seals the open end of the can and isopened by rupturing score lines in the end closure. Instead of havingscore lines, the end closure may have a friction fit within the open endof the can to close the can and be used again by insertion into the openend. With either of these end closures, it is desired to be able to gripa portion of the end closure to cause either easy rupturing of the scorelines without injury to the user or removal of the end closure from theopen end of the container without damage to the end closure when it isto be used again if it does not have the score lines.

One previously suggested end closure is disclosed in U.S. Pat. No.3,981,412 to Asmus wherein FIG. 8 shows a tab fused to be integral witha top or main panel to enable rupturing of score lines in the top. Thisrequires molding of the tab separately from the remainder of the endclosure and then fusing the tab to the top. This is a relativelyexpensive end closure. It is not a one-piece end closure but comprisestwo separate molded pieces that are fused together.

Each of U.S. Pat. No. 3,407,957 to Robinson and U.S. Pat. No. 3,415,404to Robinson relates to an end closure having a finger grip in spacedrelation to its main panel or top. Each of the aforesaid Robinsonpatents depends upon rupturing of a frangible portion connecting thefinger grip to the main panel of the end closure before any score linesare ruptured.

While the end closure of each of the aforesaid Robinson patents appearsto be a one-piece end closure, molding of the finger grip in spacedrelation to the main panel is deemed difficult if possible. This isbecause of the requirement for a steel core to be placed between thefinger grip and the main panel during molding to keep them separated andthen having to withdraw the finger grip from the steel core withoutcausing damage to the finger grip or fracturing of the frangible portionconnecting the finger grip to the main panel.

The aforesaid Robinson U.S. Pat. No. 3,415,404, has a pull ring as itsfinger grip in the embodiment of FIGS. 5-7. This requires the pull ringto be integral with an annular surrounding portion or rim of the endclosure and to have the score means in a flange fitting over the top ofthe can. This has the difficulty of the sealing compound entering thescore means when sealing to the can so that rupturing of the score meanscould be difficult.

Another end closure having a tear tab in spaced relation to its mainpanel so that it may be gripped for rupturing score lines in the mainpanel is found in U.S. Pat. No. 3,281,007 to Dorosz. Since the vertex orjunction of the score lines is at the connection of the tear tab to themain panel, the removal of the tear tab from the steel core, which hasto be disposed between the main panel and the tear tab to separate themduring molding, can easily result in rupturing along the score linesbecause of the forces applied to the tear tab in removing it from thesteel core.

A further end closure having a pull ring in spaced relation to its mainpanel so that it may be gripped for rupturing score lines in a mainpanel is disclosed in German patent application No. 26 46 604, publishedApr. 20, 1978. This end closure requires double score lines so that aportion of the main panel to which the pull ring is initially attachedcan be completely severed therefrom whereby the possibility exists thatthis portion of the panel could be severed and fall into a containerupon rupturing of the score lines. The pull ring is in the center of themain panel so as to not obtain the desired leverage produced when thepull ring is not at the center of the main panel.

FIGS. 11-13 of U.S. Pat. No. 4,380,303 to Allen et al show a one-pieceend closure formed integral with a container. FIGS. 14-16 of theaforesaid Allen et al patent show a molding apparatus for forming thisspecific one-piece end closure, which is integral with the container.The structure of the molding apparatus of the aforesaid Allen et alpatent prevents the pull ring of the aforesaid Allen et al patent frombeing attached to the main panel so that it must be attached to theannular surrounding portion of the end closure; it also requires doublescore lines to function.

The one-piece end closure of the present invention satisfactorilyovercomes the problems of the previously suggested end closures. The endclosure of the present invention is formed with a pull ring in spacedrelation to the main panel and uses a unique molding method andapparatus to mold the end closure without a steel core between the pullring and the main panel. Thus, the problems of the relatively largeforces applied to the finger gripping means to cause rupturing along thescore lines when the finger gripping means is removed from the moldingapparatus of the previously suggested end closures is avoided.

This is accomplished through forming the pull ring of a relatively thincross section, particularly with respect to the inner diameter of thepull ring, so that it has sufficient flexibility to be removed from thesteel core without being subjected to sufficient force to causerupturing of any score line in the main panel of the end closure towhich the pull ring is connected. Therefore, by the pull ring beingrelatively thin, it can collapse as it is removed from the steel core ofthe molding apparatus of the present invention.

Additionally, by providing a pull ring with a relatively large innerdiameter in comparison with its thickness, a removable mold element canbe utilized adjacent the main panel and cooperate with the steel core toform the pull ring. This avoids subjecting the pull ring to relativelylarge forces when it is removed from the molding apparatus since theremovable mold element is removed before the pull ring is withdrawn fromthe steel core.

Furthermore, the score lines are formed in the main panel of the endclosure of the present invention. In the embodiment having the scorepoint, which is the junction of two score lines with one of these scorelines initially extending from a peripheral score line, the score pointis positioned beneath the pull ring within the inner diameter of thepull ring. This makes it easier for the score lines to rupture.

The ability to mold the one-piece end closure with the pull ring inspaced relation to the main panel permits the end closure to be formedintegral with the wall of the container. This results in a portion ofthe wall of the container forming the annular surrounding portionextending from the same side of the main panel as the pull ring. Thisintegral end closure and container requires a different moldingapparatus than the molding apparatus used in forming the one-piece endclosure by itself. However, the molding apparatus includes a similararrangement as to the portion forming the pull ring in spaced relationto the main panel.

The ability to mold a one-piece end closure with the pull ring in spacedrelation to the main panel also allows the end closure to be utilized asa plug for closing an open end of a container such as a can, forexample, in which the closure may be removed from the open end of thecan by pulling on the pull ring and then reinserted into the open end ofthe can when it is desired to again close the open end of the can. Thisend closure can be molded with substantially the same molding apparatusas used for forming the one-piece molded end closure with the scorelines. The molding apparatus would have to be slightly changed to notform the score lines in the main panel of the end closure.

When used to plug the open end of the can, the can normally has afrangible closure, which can be foil or foil paper laminate, forexample, inside of the end closure. Thus, the initial opening of the canhaving the end closure as a plug requires not only removal of the endclosure but fracturing of the frangible closure. Thereafter, the endclosure is relied upon to close the open end of the can through the endclosure having a friction fit with the inner wall of the can.

A object of this invention is to provide a method for molding aone-piece end closure having finger gripping means spaced from its mainpanel irrespective of whether the end closure has score lines or has afriction fit within an open end of a container.

Another object of this invention is to provide a method for molding aone-piece end closure integral with a wall of a container.

Other objects of this invention will be readily perceived from thefollowing description, claims, and drawings.

This invention relates to a method of molding a one-piece end closurefor closing an open end of a container in which the end closure includesa main panel having an annular surrounding portion at its periphery, apull ring disposed in spaced and substantially parallel relation to themain panel, and means connecting the pull ring to the main panel. Themethod includes injecting molten plastic into a mold shaped to form theend closure and including first mold means having molding surface means,second mold means having first and second molding surface means, andthird mold means having first and second molding surface means, thesecond mold means having passage means to receive a portion of the thirdmold means, the passage means in the second mold means having the secondmolding surface means of the second mold means and the portion of thethird mold means having the second molding surface means of the thirdmold means cooperating with the second molding surface means of thesecond mold means to form the pull ring when the portion of the thirdmold means is disposed within the passage means in the second mold meansso that the first molding surface means of the third mold means is inthe same plane as at least the portion of the first molding surfacemeans of the second mold means surrounding the first molding surfacemeans of the third mold means. The portion of the third mold means isdisposed within the passage means in the second mold means so that thefirst molding surface means of the third mold means is in the same planeas at least the portion of the first molding surface means of the secondmold means surrounding the first molding surface means of the third moldmeans prior to injecting the molten plastic to form the end closure. Themolten plastic is injected between the molding surface means of thefirst mold means and the first molding surface means of each of thesecond mold means and the third mold means to form the main panel andthe annular surrounding portion of the formed end closure. The moltenplastic is supplied from between the molding surface means of the firstmold means and the first molding surface means of each of the secondmold means and the third mold means to between the second moldingsurface means of each of the second mold means and the third mold meansthrough communicating means in the second mold means with the connectingmeans being formed by the molten plastic in the communicating means.Relative movement is produced between the third mold means and thesecond mold means to withdraw a portion of the third mold means from thepassage means in the second mold means prior to producing relativemovement between the first mold means and the second and third moldmeans without shearing of any molded material so that the pull ring isfree to collapse prior to relative movement between the first mold meansand the second and third mold means to enable the pull ring to passthrough the passage means in the second mold means when the formed endclosure is disengaged from the first molding surface means of the secondmold means. Relative movement is produced between the first mold meansand the second and third mold means substantially parallel to thedirection of relative movement between the third mold means and thesecond mold means to disengage the formed end closure from one of themolding surface means of the first mold means and the first moldingsurface means of the second mold means without any shearing of themolded material. The formed end closure is then disengaged from theother of the molding surface means of the first mold means and the firstmolding surface means of the second mold means.

The attached drawings illustrate preferred embodiments of the invention,in which:

FIG. 1 is a top plan view of one form of an end closure of the presentinvention having score lines for rupturing to enable opening of the endclosure;

FIG. 2 is a sectional view of the end closure of FIG. 1 and taken alongline 2--2 of FIG. 1 and showing the end closure mounted on the end of acan;

FIG. 3 is an enlarged fragmentary sectional view of a portion of the endclosure of FIG. 1 and showing a second end closure stacked thereon;

FIG. 4 is a top plan view of another form of an end closure of thepresent invention having a friction fit within an open end of a can withthe end closure capable of being used again to close the open end of thecan;

FIG. 5 is a sectional view, partly in elevation, of the end closure ofFIG. 4 and taken along line 5--5 of FIG. 4 and shown disposed in a canwith another can resting thereon;

FIG. 6 is an enlarged fragmentary sectional view of a portion of the endclosure of FIG. 4 showing it in a stacking arrangement with another ofthe end closures of FIG. 4;

FIG. 7 is a sectional view, partly schematic, of a portion of a moldingapparatus for forming the end closure of FIG. 1 with the moldingapparatus in its closed or molding position and taken along line 7--7 ofFIG. 10;

FIG. 8 is a fragmentary sectional view of a portion of the moldingapparatus of FIG. 7 with molding of the end closure having beencompleted and the molded end closure removed from a cavity of themolding apparatus;

FIG. 9 is a fragmentary sectional view of a portion of the moldingapparatus of FIG. 7 in its fully open position with the molded one-pieceend closure stripped from the molding apparatus;

FIG. 10 is a side elevational view of the molding apparatus of FIGS. 7-9for forming the end closure of FIG. 1;

FIG. 11 is a fragmentary sectional view of a portion of a moldingapparatus, similar to FIGS. 7-9, but showing the different structureemployed for molding the end closure of FIGS. 4-6;

FIG. 12 is a fragmentary sectional view of a portion of a moldingapparatus, similar to FIGS. 7-9, but showing the different structureemployed for molding an end closure without score lines;

FIG. 13 is an enlarged fragmentary sectional view of a portion of themolding apparatus of FIGS. 7-9;

FIG. 14 is a top plan view of a further embodiment of an end closure ofthe present invention having a single continuous score line forrupturing to enable opening of the end closure;

FIG. 15 is a sectional view of the end closure of FIG. 14 showing theend closure mounted on the end of a container and taken along line15--15 of FIG. 14;

FIG. 16 is a fragmentary sectional view of a portion of a moldingapparatus, similar to FIGS. 7-9, but showing the different structureemployed for molding the end closure of FIG. 14;

FIG. 17 is a top plan view of another form of an end closure of thepresent invention in which the end closure is formed integral with awall of a container and the end closure has a single continuous scoreline for rupturing to enable opening of the end closure;

FIG. 18 is a fragmentary longitudinal sectional view of the integral endclosure and container wall of FIG. 17 and taken along line 18--18 ofFIG. 17;

FIG. 19 is a fragmentary sectional view of a portion of a moldingapparatus for forming the integral end closure and container wall ofFIG. 17 with the molding apparatus in its closed or molding position;

FIG. 20 is a fragmentary sectional view, partly schematic, of a portionof the molding apparatus of FIG. 19 with molding of the integral endclosure and container wall completed and the first parting of portionsof the molding apparatus completed;

FIG. 21 is a fragmentary sectional view, partly schematic, of themolding apparatus of FIG. 19 with the second parting of portions of themolding apparatus completed;

FIG. 22 is a fragmentary sectional view of a portion of the moldingapparatus of FIG. 19 in its fully open position with the integral endclosure and container wall about to be stripped from the moldingapparatus; and

FIG. 23 is an end elevational view of a core plug of the moldingapparatus of FIG. 19.

Referring to the drawings and particularly FIG. 1, there is shown an endclosure 10 for closing an open end 11 (see FIG. 2) of a container 12such as a can, for example. The container 12 may be a spiral wound papercan, for example, lined with an aluminum foil 12' having a polyethylenefilm laminate 13 to seal and function as a coating.

The end closure 10 could be welded ultrasonically to the polyethylenefilm laminate 13, for example, of the container 12 as one means ofsealing the end closure 10 to the container 12. The end closure 10 alsocould be sealed to the container 12 by an adhesive such as glue, forexample. Another means of attaching the end closure 10 in a sealingrelation to the container 12 could be by induction heat sealing if thematerials of the end closure 10 and the container 12 are similar such aspolyethylene and polypropylene, for example, and they melt at similartemperatures.

The end closure 10 may be formed of any suitable thermal plastic such aslinear low density polyethylene, low density polyethylene, high densitypolyethylene, polypropylene, polycarbonates, and nylon, for example. Anyother suitable material capable of injection molding may be utilized toform the end closure 10.

The end closure 10, which is circular shaped although it could be anyshape depending on the shape of the open end 11 of the container 12,includes a main panel or top 14 having an annular surrounding portion15, which is a skirt, for example, at its periphery. The annularsurrounding portion 15 extends substantially perpendicular from the mainpanel 14 but at an angle slightly greater than 90° such as 92°, forexample.

The end of the annular surrounding portion 15 (see FIG. 2) remote fromthe main panel 14 has a first annular portion 16 extending outwardlytherefrom substantially perpendicular thereto and substantially parallelto the main panel 14. A second annular portion 17 extends from the endof the first annular portion 16 substantially perpendicular thereto.This enables formation of a groove 18 between the annular surroundingportion 15, the first annular portion 16, and the second annular portion17 so that the groove 18 receives the container 12 for sealing relationtherewith.

As shown in FIG. 1, the main panel 14, which is substantially flat, ofthe end closure 10 has a peripheral score line 19 at its junction withthe annular surrounding portion 15. The peripheral score line 19 iscontinuous and extends around the entire circumference of the main panel14.

The main panel 14 has a first score line 20 extending from theperipheral score line 19 and a second score line 21 extending from thefirst score line 20. The first score line 20 and the second score line21 have a junction at a score point 22.

The first score line 20 includes a curved portion 23 extending for ashort distance from the peripheral score line 19 and a straight portion24 extending from the curved portion 23 to the score point 22. While theportion 23 of the first score line 20 is preferably curved, it should beunderstood that the entire length of the first score line 20 could bestraight, if desired. The first score line 20 also could be curved forits entire length, if desired.

The second score line 21 is a portion of a circle having a differentcenter than the center of the main panel 14. The second score line 21has its center 25 displaced from the center of the main panel 14. Ifdesired, the second score line 21 could be formed on the same center asthe main panel 14; this is the center of the peripheral score line 19.However, it is preferred for the distance between the second score line21 and the peripheral score line 19 to decrease to enable easierrupturing of the score lines 19-21 by pulling on a pull ring 26.

The pull ring 26 is disposed in spaced and substantially parallelrelation to the top or main panel 14 as shown in FIG. 2. The pull ring26 is connected to the main panel 14 by a tenon or connecting portion27. The tenon 27 extends from inside of the score point 22 (see FIG. 1)to a portion of the inner diameter of the pull ring 26. The tenon 27also extends to a portion of the main panel 14 exterior of the outerdiameter of the pull ring 26 as shown in FIG. 2. However, as shown inFIG. 1, no portion of the tenon 27 crosses any portion of the scorelines 20 and 21.

The pull ring 26 has an inner diameter several times larger than itsthickness. The tenon 27 spaces the pull ring 26 further from the mainpanel 14 than the thickness of the pull ring 26. For example, the pullring 26 may have an inner diameter of 0.750", a thickness of 0.030", anda distance of the pull ring 26 from the main panel 14 of 0.125".

By having the first score line 20 and the second score line 21 intersectat a substantially right angle at the score point 22, rupturing of thescore lines 20 and 21 is easier to start by pulling on the pull ring 26.It should be understood that the first score line 20 and the secondscore line 21 could have other angles of intersection but rupturing ofthe score lines 20 and 21 would not be as easy to start as with thesharp point produced by the substantially perpendicular intersection ofthe first score line 20 and the second score line 21.

Pulling on the pull ring 26 causes initial rupturing along the firstscore line 20 and the second score line 21. When rupturing along thefirst score line 20 is completed, rupturing occurs along a portion ofthe peripheral score line 19 in conjunction with rupturing of theremainder of the second score line 21. When rupturing of the secondscore line 21 is completed, the remainder of the peripheral score line19 is ruptured to remove the main panel 14 and provide access to theinterior of the container 12 (see FIG. 2).

Referring to FIG. 4, there is shown an end closure 30 formed without anyscore lines and utilized for closing an open end 31 (see FIG. 5) of acontainer 32 such as a can, for example. The container 32 has a bead 33at its upper end with which the end closure 30 has a tight friction fit.There is usually a frangible seal (not shown) within the container 32since the end closure 30 has only a friction fit with the bead 33. Thecontainer 32 may be made of spiral wound cardboard, for example.

The end closure 30 includes a main panel 34, which is substantiallyflat, having an annular surrounding portion 35 extending from itsperiphery at an angle slightly less than 90° and preferably 87°. Thisangular relation insures that there is a tight friction fit of the endclosure 30 within the open end 31 of the container 32 through engagementof the annular surrounding portion 35 with the bead 33 of the container32. The annular surrounding portion 35 has an annular flange 36extending therefrom near the end of the annular surrounding portion 35remote from the main panel 34.

The end closure 30 has a pull ring 37 disposed in spaced andsubstantially parallel relation to the main panel 34 and connected tothe main panel 34 by a tenon or connecting portion 38. Thus, pulling onthe pull ring 37 will remove the end closure 30 from the open end 31 ofthe container 32. The inner diameter of the pull ring 37 is severaltimes larger than its thickness, and the tenon 38 spaces the pull ring37 farther from the main panel 34 than the thickness of the pull ring37.

Another container 39, which is the same as the container 32, can bemounted on the annular flange 36 of the end closure 30 on the container32 in a stacked relation. The container 39 has its bottom bead 40resting on the annular flange 36 of the end closure 30. The container 39has a closure 41 for closing its bottom end.

As shown in FIG. 6, the main panel 34 has an annular ring 42 extendingfrom its surface opposite to that from which the tenon 38 (see FIG. 5)extends. The ring 42 (see FIG. 6) is utilized to enable stacking of theend closures 30 in a stacking arrangement since the stacking ring 42 isinside of the end of the annular surrounding portion 35 of the lower endclosure 30.

Referring to FIG. 7, there is shown a molding apparatus 50 for formingthe end closure 10 by injection molding. The molding apparatus 50includes a stationary top clamp plate 51, a runner plate 52, and acavity plate 53 connected to each other. A cavity insert 54 is mountedwithin the cavity plate 53 and has a recess or cavity 55 (see FIG. 8)therein.

The stationary top clamp plate 51 (see FIG. 7) and the runner plate 52cooperate to form a passage 56 therebetween and communicating with apassage 57 in the runner plate 52 and a passage 58 in the cavity insert54. Molten plastic flows through the passages 56-58 and an orifice 59 atthe end of the passage 58 into the recess 55 (see FIG. 8) in the cavityinsert 54.

The end closure 10 is molded between the recess 55 in the cavity insert54, a movable core 60 having an annular portion 61 extending into therecess 55, a core plug 62 secured by screws 63 (one shown) to themovable core 60 and surrounded by the annular portion 61 of the movablecore 60, a stripper ring 64 surrounding part of the annular portion 61of the movable core 60, and a handle shaft pin 65 extending into apassage 66 in the core plug 62. The core plug 62 has a cavity 67 (seeFIG. 9) surrounding the passage 66 communicating through a passage 68 inthe core plug 62 with the recess 55 in the cavity insert 54 to allowmolten plastic to be supplied from the recess 55 to the cavity 67. Thepassage 68 is formed in the core plug 62 and communicates with thepassage 66 when the handle shaft pin 65 is removed. Accordingly, thehandle shaft pin 65 must be in the position of FIG. 7 for the passage 68to have plastic flow into the cavity 67. Thus, the pull ring 26 (seeFIG. 8) of the second end closure 10 is formed in the cavity 67 (seeFIG. 7) and the tenon 27 (see FIG. 8) is formed in the passage 68 (seeFIG. 7) when the handle shaft pin 65 is in the position of FIG. 7.

The handle shaft pin 65 is mounted on a force plate 69, which isattached to a movable bottom clamp plate 70 for movement therewith. Amovable core plate 71, which has its upper end abutting a shoulder 72 ofthe movable core 60 and retained thereagainst by a retaining ring 73,abuts the force plate 69 when the molding apparatus 50 is in the closedposition of FIG. 7. However, the movable core plate 71 is continuouslyurged away from the force plate 69 by springs 74 (one shown), whichextend between the movable bottom clamp plate 70 and the movable coreplate 71. The springs 74 extend through passages 75 in the force plate69.

The stripper ring 64 has a stripper ring retainer 76 secured thereto byscrews 77 (one shown). A stripper plate 78, which has a portion 79projecting into an annular recess 80 formed in portions of the stripperring 64 and the stripper ring retainer 76, rests on top of the movablecore plate 71 when the molding apparatus 50 is in the closed position ofFIG. 7. The stripper plate 78 holds the stripper ring 64 in the desiredposition.

After the end closure 10 has been formed by supplying the molten plasticthrough the orifice 59 to the recess 55 in the cavity insert 54 with themolding apparatus 50 in the closed position of FIG. 7, the movablebottom clamp plate 70 is moved in a direction away from the stationarytop clamp plate 51, the runner plate 52, and the cavity plate 53 bysuitable moving means 80' such as a hydraulic cylinder, for example.This movement of the movable bottom clamp plate 70 initially carrieswith it the force plate 69 and the handle shaft pin 65.

Because of the force of the springs 74, the movable core plate 71, themovable core 60, the core plug 62, the stripper ring 64, the stripperring retainer 76, and the stripper plate 78 do not initially move withthe movable bottom clamp plate 70. As a result, the handle shaft pin 65is initially withdrawn from the upper portion of the passage 66 in thecore plug 62 so that the pull ring 26 (see FIG. 8) is no longer held bythe handle shaft pin 65 within the cavity 67 (see FIG. 7) in the coreplug 62 and the tenon 27 (see FIG. 8) is no longer held within thepassage 68 (see FIG. 7) in the core plug 62.

When the springs 74 are fully extended, there will be a space betweenthe force plate 69 and the movable core plate 71 as shown in FIG. 8. Atthis time, each of heads 81 (one shown) of bolts 82 (one shown), whichare attached to the force plate 69, engages one of a plurality ofannular shoulders 83 (one shown) in the movable core plate 71 to causethe movable core plate 71 to follow the movement of the movable bottomclamp plate 70. This also causes the movable core 60, the core plug 62,the stripper ring 64, the stripper ring retainer 76, and the stripperplate 78 to move therewith.

After separation of the force plate 69 from the movable core plate 71,continued movement of the movable bottom clamp plate 70 withdraws thecore plug 62 and the annular portion 61 of the movable core 60 from thecavity 55 in the cavity insert 54 to the position of FIG. 8. In thisposition, the end closure 10 is still supported on the core plug 62, theannular portion 61 of the movable core 60, and the stripper ring 64.

With the molding apparatus 50 in the position of FIG. 8, knock-out rodsor bars 84 (one shown), which extend through aligned passages 85 (oneshown) in the movable bottom clamp plate 70, passages 86 (one shown) inthe force plate 69, and passages 87 (one shown) in the movable coreplate 71, are activated by suitable moving means such as hydraulic means87' (see FIG. 7), for example, to move the stripper plate 78 away fromthe movable core plate 71 as shown in FIG. 9. The movement of thestripper plate 78 by the knock-out rods 84 (see FIG. 8) is limited byeach of a plurality of heads 88 (one shown) of bolts 89 (one shown),which are attached to the movable core plate 71, engaging one of aplurality of annular shoulders 90 (one shown) in the stripper plate 78.This controls maximum movement of the stripper plate 78 away from themovable core plate 71. This movement of the stripper plate 78 moves thestripper ring 64 beyond the annular portion 61 of the movable core 60,as shown in FIG. 9, to strip the end closure 10 from the movable core 60and the core plug 62.

When the molding apparatus 50 is in the closed position of FIG. 7, theannular portion 61 of the movable core 60 has its end surface 91 in thesame plane as an end surface 92 of the core plug 62, and an end surface93 of the handle shaft pin 65. This insures that the main panel 14 ofthe end closure 10 is substantially flat and in a single plane.

To form the peripheral score line 19 (see FIG. 1) of the end closure 10,the recess 55 (see FIG. 8) in the cavity insert 54 has its wall orsurface 93' formed with a step 94 extending around its periphery. Thisproduces a relatively thin portion of the main panel 14 (see FIG. 3) ofthe end closure 10 to create the peripheral score line 19.

A projection 95 (see FIG. 8) extends from the wall or surface 93' of therecess 55 and has the configuration of the first score line 20 (seeFIG. 1) and the second score line 21 of the end closure 10. Thisproduces a relatively thin portion of the main panel 14 to create thefirst score line 20 and the second score line 21.

When the end closure 30 (see FIG. 4) is to be formed by the moldingapparatus 50 (see FIG. 7), it is necessary to have a cavity insert 96(see FIG. 11) instead of the cavity insert 54 (see FIG. 7) with thecavity insert 96 (see FIG. 11) having its recess 97 shaped differently.It also is necessary to replace the movable core 60 (see FIG. 7) with amovable core 98 (see FIG. 11) having its annular portion 99 configureddifferently. The configuration of the core plug 62 will not have to bechanged. The use of the cavity insert 96 in the molding apparatus 50(see FIG. 7) enables the end closure 30 (see FIG. 4) to be produced.

Referring to FIG. 12, there is shown an end closure 100, which issimilar to the end closure 30 (see FIG. 4) except that it has a mainpanel 101 (see FIG. 12) formed with a recess central portion 102 and anouter surrounding portion 103. This also requires a cavity insert 104instead of the cavity insert 54 (see FIG. 7). The cavity insert 104 (seeFIG. 12) has a different shaped recess or cavity 105. This also requiresa different shaped movable core 106 with its annular portion 107 beingshaped differently.

The operation of the molding apparatus 50 (see FIG. 7) to produce eitherthe end closure 30 (see FIG. 4) or the end closure 100 (see FIG. 12) isthe same as that described for forming the end closure 10 (see FIG. 1).

Coolant such as water is supplied to the cavity insert 54 (see FIG. 7)through a coolant channel 108. O-rings 109 and 110 are disposed onopposite sides of the coolant channel 108 to prevent leakage.

Coolant also is supplied to the core plug 62 through a substantiallyhorizontal coolant channel 111 (see FIG. 10) in the movable core plate71 (see FIG. 7), a substantially vertical coolant channel 112 (see FIG.10) in the movable core 60 (see FIG. 7), and an annular coolant channel113 in the core plug 62. The coolant channel 112 (see FIG. 10) alsosupplies coolant through the coolant channel 113 for a second coolantchannel 114 in the core plug 62 (see FIG. 7). O-rings 115 and 116 in themovable core 60 on opposite sides of the coolant channel 112 (see FIG.10) adjacent its connection to the coolant channel 111 prevent leakagebetween the movable core plate 71 (see FIG. 7) and the movable core 60.O-rings 117, 118, and 119 are utilized to prevent leakage of the coolantbetween the movable core 60 and the core plug 62. It should beunderstood that the coolant channels 108, 113, and 114 have returnpassages such as coolant channels 119' (see FIG. 10) to return thecoolant to the source of coolant.

Four of the end closures 10 (see FIG. 1) could be simultaneously formedin the molding apparatus 50 of FIG. 10. The cavity plate 53 (see FIG. 7)has four of the cavity inserts 54. There are four of the movable cores60, the core plugs 62, the stripper rings 64, the handle shaft pins 65,and the stripper ring retainers 76.

As shown in FIG. 10, guide pins 120 are employed adjacent the fourcorners of the molding apparatus 50. The guide pins 120 are mounted onthe movable bottom clamp plate 70 (see FIG. 7).

Referring to FIG. 14, there is shown an end closure 121 for closing anopen end 122 (see FIG. 15) of a container 123 such as a can, forexample. The container 123 may be the same as the container 12 (see FIG.2), for example.

The end closure 121 (see FIG. 15), which is circular shaped although itcould be any shape depending on the shape of the open end 122 of thecontainer 123, includes a main panel or top 124, which comprises acentral portion 125 surrounded by an outer portion 126. The outerportion 126 of the main panel 124 has an annular surrounding portion127, which is a skirt, for example, at its periphery. The annularsurrounding portion 127 extends substantially perpendicular from theouter portion 126 of the main panel 124 but at an angle slightly greaterthan 90° such as 92°, for example.

The end of the annular surrounding portion 127 remote from the mainpanel 124 has an annular flange 128 extending outwardly therefromsubstantially perpendicular thereto and substantially parallel to themain panel 124. The annular flange 128 may be attached in a sealingrelation to the container 123 by any suitable means such as adhesive,for example.

As shown in FIG. 15, the outer portion 126 of the main panel 124 is in adifferent plane than the central portion 125 of the main panel 124. Asshown in FIG. 14, a single continuous score line 129 is formed in theouter portion 126 of the main panel 124 at the periphery of the centralportion 125. Thus, the single continuous score line 129 is a peripheralscore line surrounding the central portion 125 of the main panel 124 andis adjacent the junction of the central portion 125 and the outerportion 126.

As shown in FIG. 15, a pull ring 130 is disposed in spaced andsubstantially parallel relation to the main panel 124. The pull ring 130is connected to the central portion 125 of the main panel 124 by a tenonor connecting portion 131. The tenon 131 extends from the centralportion 125 to the pull ring 130. The tenon 131 also extends to aportion of the central portion 125 of the main panel 124 exterior of theouter diameter of the pull ring 130 as shown in FIG. 15.

The pull ring 130 has the same relative dimensions as the pull ring 26(see FIG. 1). The pull ring 130 (see FIG. 14) has its center spaced fromthe center of the main panel 124. The tenon 131 is positioned so thatinitial pulling on the pull ring 130 causes rupturing initially of theportion of the single continuous score line 129 adjacent the tenon 131.

The complete severing of the single continuous score line 129 results inthe central portion 125 of the main panel 124 being completely severedfrom the outer portion 126 of the main panel 124. Because the pull ring130 remains attached to the main panel 124, the central portion 125 ofthe main panel 124 may be easily lifted from the remainder of the endclosure 121 to provide access to the interior of the container 123 (seeFIG. 15).

Referring to FIG. 16, there is shown a molding apparatus 132, which issubstantially the same as the molding apparatus 50 (see FIG. 7), forforming the end closure 121 (see FIG. 16). A cavity insert 133 isutilized instead of the cavity insert 54 (see FIG. 7). The cavity insert133 (see FIG. 16) has a different shaped recess or cavity 134. Themolding apparatus 132 also requires a different shaped movable core 135than the core 60 (see FIG. 7) with the core 135 (see FIG. 16) having adifferent shaped annular portion 136.

The recess 134 in the cavity insert 133 has a molding surface 137positioned very close to a molding surface 138 of the annular portion136 of the core 135 for forming the single continuous score line 129(see FIG. 14) in the main panel 124 of the end closure 121. Theoperation of the molding apparatus 132 (see FIG. 16) is the same as theoperation of the molding apparatus 50 (see FIG. 7) for forming the endclosure 10 (see FIG. 1).

Referring to FIGS. 17 and 18, there is shown an end closure 140 formedintegral with a cylindrical wall 141 of a container 142. The end closure140 and the container 142 may be formed of any suitable thermoplasticsuch as high density polyethylene, polypropylene, or styrene, forexample. Any other suitable material capable of injection molding may beutilized to form the end closure 140 and the container 142. Thecylindrical wall 141 of the container 142, which is circular shapedalthough it could be any shape, is formed integral with a main panel ortop 143, which is circular shaped, of the end closure 140.

The main panel 143, which is substantially flat, has a single continuousscore line 144 formed therein. While the single continuous line 144 isshown spaced from the cylindrical wall 141 of the container 142, thesingle continuous score line 144 could be in the main panel 143 adjacentits junction with the cylindrical wall 141 of the container 142 ifdesired.

A pull ring 145 is disposed in spaced parallel relation to the mainpanel 143 as shown in FIG. 18. The pull ring 145 is connected to themain panel 143 by a tenon or connecting portion 146. The tenon 146extends from the main panel 143 inside of the continuous score line 144to a portion of the pull ring 145. The tenon 146 extends to a portion ofthe main panel 143 exterior of the outer diameter of the pull ring 145as shown in FIG. 17. While the tenon 146 is adjacent the singlecontinuous score line 144, no portion of the tenon 146 crosses anyportion of the single continuous score line 144.

The pull ring 145 has the same relative dimensions as the pull ring 26(see FIG. 1). The center of the pull ring 145 (see FIG. 17) is spacedfrom the center of the main panel 143.

The tenon 146 is positioned so that initial pulling on the pull ring 145causes rupturing initially of the portion of the single continuous scoreline 144 adjacent the tenon 146. The complete severing of the singlecontinuous score line 144 results in a portion of the main panel 143within the single continuous score line 144 being completely severedfrom the portion of the main panel 143 exterior of the single continuousscore line 144. The pull ring 145 remains attached to the severedportion of the main panel 143 so that it may be easily lifted from theremainder of the main panel 143 to provide access to the interior of thecontainer 142 (see FIG. 18).

The portion of the cylindrical wall 141 of the container 142 extendingbeyond the main panel 143 on the same side as the pull ring 145constitutes an annular surrounding portion at the periphery of the mainpanel 143 of the end closure 140. The end of the cylindrical wall 141extends beyond the top of the pull ring 145. The end of the cylindricalwall 141 has an annular flange or bead 147 thereon. The other end of thecylindrical wall 141 of the container 142 has an annular flange or bead148, which has a slightly smaller outer diameter than the outer diameterof the annular flange or bead 147. The annular flange or bead 148defines an open end of the container 142 with the open end being closedby a closure (not shown) such as a metal closure cooperating with thebead 148. The flange 147 is of a size to enable a plastic closure to befitted thereover when the main panel 143 has been removed and it isdesired to close this opened end of the container 142 to protect theremaining contents.

Referring to FIG. 19, there is shown a molding apparatus 150 for formingthe end closure 140 (see FIG. 18) and the cylindrical wall 141 of thecontainer 142 integral therewith. The molding apparatus 150 (see FIG.22) includes a stationary clamp plate 151, a force base 152, a core ring153, a force plate 154, and a force ring plate 155.

The stationary clamp plate 151 is connected to the force base 152 and tothe force plate 154. The force plate 154, which surrounds the force base152, has the core ring plate 155 connected thereto. The core ring 153,which is surrounded by the core ring plate 155, is connected to the corering plate 155 by a retainer ring 156.

A heater probe 157 is mounted in the stationary clamp plate 151 and hasa passage 158 extending therethrough. The heater probe 157 is retainedwithin the stationary clamp plate 151 by a ring 159, which is secured tothe stationary clamp plate 151 by screws (not shown). The heater probe157 supports a heater band 160 for applying heat to molten plasticflowing through the passage 158 to maintain the plastic molten. Themolten plastic is supplied to the passage 158 from a passage 161 in amachine nozzle 162, which fits within a recess 163 in the end of theheater probe 157.

The passage 158 in the heater probe 157 supplies the molten plastic to apassage 164 in a sprue base 165, which is positioned within an enlargedrecess 166 in the force base 152. The heater probe 157 has a portionextending into a recess 166' in the sprue base 165, which has a pistonshaft 167 attached thereto by screws 168 (one shown). The piston shaft167 is disposed in surrounding and spaced relation to an elongatedportion 169 of the sprue base 165.

The elongated portion 169 of the sprue base 165 has a nozzle tip 170(see FIG. 19) attached thereto by threads 171. The nozzle 170 has apassage 172 to receive the molten plastic flowing through the passage164 in the sprue base 165 (see FIG. 22).

A sprue heater shield 173, which is secured to the sprue base 165 bythreads 173', is positioned in the space between the elongated portion169 of the sprue base 165 and the piston shaft 167. The sprue heatershield 173 is spaced from both the elongated portion 169 of the spruebase 165 and the piston shaft 167.

The sprue heater shield 173 has a ring 174 (see FIG. 19) at its end andspaced from an outer surface 175 of the nozzle tip 170 to receive moltenplastic in an annular space 175' therebetween when it initially flowsinto the passage 172 in the nozzle tip 170. The molten plastic flowsinto the annular space 175' and hardens to form insulation around theouter surface 175 of the nozzle tip 170. The nozzle tip 170 extends intoa recess 176 in a force cap 177, which is secured by threads 178 to thepiston shaft 167.

The plastic is maintained molten by a heater band 179 (see FIG. 22),which comprises a plurality of coils. The desired heat profile isobtained through disposing more of the coils of the heater band 179 ateach end of the elongated portion 169 of the sprue base 165 than in theintermediate portion.

The force base 152 has an elongated hollow portion 180 extending into acavity 181 (see FIG. 19) in a cavity plate 182. The elongated hollowportion 180 of the force base 152 surrounds the piston shaft 167 and isin engagement therewith. The elongated hollow portion 180 of the forcebase 152 has an angled surface 183 against which an angled surface 184of the force cap 177 engages during molding of the end closure 140 andthe container 142. The angled surfaces 183 and 184 are preferably at 50°to the horizontal although such is not a requisite for satisfactoryoperation.

During molding, the molten plastic flows from the passage 172 in thenozzle tip 170 into the recess 176 in the force cap 177 and exitstherefrom through an orifice 185 in an end surface 186 of the force cap177. The end surface 186 of the force cap 177 functions as one of itsmolding surfaces.

A movable core plug 187, which is attached by screws 188 to a movablecore 189, has its end surface 190, which is a molding surface, spacedfrom the end surface 186 of the force cap 177 to form a portion of arecess therebetween into which the molten plastic flows from the orifice185. The screws 188 also connect a water ring 191 to the movable core189.

The core plug 187 has a passage 192 extending therethrough with itscross section decreasing towards the end surface 190. The passage 192has a handle post 193 slidable therein with its end surface 194 in thesame plane as the end surface 190 of the core plug 187 and spaced fromthe end surface 186 of the force cap 177 to form a portion of the recessinto which the molten plastic flows from the orifice 185. Thus, the endsurface 190 of the core plug 187 and the end surface 194 of the handlepost 193 constitute molding surface means for cooperating with the endsurface 186 of the force cap 177 to form the main panel 143 (see FIG.17) of the end closure 140.

The core plug 187 (see FIG. 19) has a cavity 195 surrounding the passage192 and communicating through a passage 196 in the core plug 187 withthe recess into which the molten plastic flows from the orifice 185 inthe force cap 177 to allow the molten plastic to be supplied to thecavity 195. The passage 196 is formed in the core plug 187 andcommunicates with the passage 192 in the core plug 187 when the handlepost 193 is removed. Accordingly, the handle post 193 must be in theposition of FIG. 19 for plastic to flow through the passage 196 into thecavity 195. Thus, the pull ring 145 (see FIG. 18) of the end closure140, which is integral with the cylindrical wall 141 of the container142, is formed in the cavity 195 (see FIG. 19) and the tenon 146 (seeFIG. 18) is formed in the passage 196 (see FIG. 19) when the handle post193 is in the position of FIG. 19.

The core plug 187 has an outer surface 197 spaced from the cavity 181 inthe cavity plate 182 to form a portion of the recess in which a portionof the cylindrical wall 141 (see FIG. 18) of the container 142 is formedalong with the annular flange or bead 147. The annular flange or bead147 is formed by an annular groove 198 (see FIG. 19) in the cavity plate182 adjacent its corner. The remainder of the cylindrical wall 141 (seeFIG. 18) is formed in an annular space between the elongated hollowportion 180 (see FIG. 22) of the force base 152 and the wall of thecavity 181 (see FIG. 19) in the cavity plate 182. The annular flange orbead 148 (see FIG. 18) of the free end of the cylindrical wall 141 ofthe container 142 is formed between a curved surface 199 (see FIG. 19)of the force base 152 and a curved surface 200 of the cavity plate 182.

The handle post 193 (see FIG. 20) is mounted on a movable clamp plate201 for movement together. The handle post 193 is prevented fromrotation by a dowel pin 201' disposed in the handle post 193 and themovable clamp plate 201.

When the molding apparatus 150 is in the closed position of FIG. 19, themovable clamp plate 201 (see FIG. 20) abuts the movable core 189.However, the movable core 189 is continuously urged away from themovable clamp plate 201 by springs 202 (one shown), which extend betweenthe movable clamp plate 201 and the movable core 189. The springs 202extend into recesses 203 in the movable core 189.

After the end closure 140 (see FIG. 18) and the cylindrical wall 141 ofthe container 142 have been formed by supplying the molten plasticthrough the orifice 185 (see FIG. 19) in the force cap 177 with themolding apparatus 150 in the closed position of FIG. 19, the movableclamp plate 201 (see FIG. 20) is moved away from the movable core 189 bysuitable moving means 204 such as a hydraulic cylinder, for example.This movement of the movable clamp plate 201 initially carries with itthe handle post 193.

Because of the force of the springs 202, the movable core 189 does notinitially move with the movable clamp plate 201. As a result, the handlepost 193 is initially withdrawn from the portion of the passage 192 inthe core plug 187 having the cavity 195 so that the pull ring 145 (seeFIG. 17) is no longer held by the handle post 193 (see FIG. 19) withinthe cavity 195 in the core plug 187.

When the springs 202 (see FIG. 20) are fully extended, there will be aspace between the movable clamp plate 201 and the movable core 189 asshown in FIG. 20. At this time, each of heads 205 (one shown) of bolts206 (one shown), which are attached to the movable clamp plate 201,engages one of a plurality of annular shoulders 207 in the movable core189 to cause the movable core 189 to follow the movement of the movableclamping plate 201. This also causes the movable core plug 187 to movetherewith since the movable core plug 187 is attached to the movablecore 189 by the screws 188.

During this separation of the movable clamping plate 201 from themovable core 189, springs 208 (one shown), which extend between themovable clamp plate 201 and a cavity retainer plate 209 through passages210 in the movable core 189, hold the cavity retainer plate 209 againstfollowing movement of the movable core 189. The cavity retainer plate209 surrounds the water ring 191 and is attached to a cavity ring 211(see FIG. 19), which surrounds the cavity plate 182, by screws 212 (oneshown). The cavity retainer plate 209 (see FIG. 20) also is attached byscrews 213 (one shown) to a cavity plate 214, which surrounds the cavityring 211 (see FIG. 19).

Because of the force of the springs 208, the cavity retainer plate 209,the cavity ring 211, and the cavity plate 214 do not initially move whenthe movable core 189 moves with the movable clamp plate 201 (see FIG.20). However, the initial movement of the movable core 189 does withdrawthe movable core 189 and the movable core plug 187 from the position ofFIG. 19 to the position of FIG. 20.

When the springs 208 (see FIG. 21) are fully extended, there will be aspace between the movable core 189 and the cavity retainer plate 209 andbetween the movable core 189, the movable core plug 187, and the waterring 191 and the cavity plate 182 and the force cap 177 shown in FIG.21. At this time, each of heads 215 (one shown) of bolts 216 (oneshown), which are attached to the movable core 189, engages one of aplurality of annular shoulders 217 (one shown) in the cavity retainerplate 209 to cause the cavity retainer plate 209 to follow the movementof the movable clamp plate 201 and the movable core 189. This alsocauses the cavity ring 211, the cavity plate 214, and the cavity plate182 to move therewith. The cavity plate 182 moves therewith because anannular shoulder 218 (see FIG. 19) on the cavity ring 211 engages anannular shoulder 219 on the cavity plate 182.

This motion of the cavity retainer plate 209, the cavity ring 211, thecavity plate 214, and the cavity plate 182 continues until there isenough clearance for the molded end closure 140 (see FIG. 22) and theintegral cylindrical wall 141 of the container 142 to fall freely whenejected from the position on the force cap 177 and the elongated hollowportion 180 of the force base 152. This position is shown in FIG. 22.

At this time, pressurized air is supplied from a pressurized air source(not shown) through an air line 220 in the stationary clamp plate 151 tofour equally angularly spaced air passages 221 (one shown) in the spruebase 165 through an annular chamber 222. The annular chamber 222 isformed in the sprue base 165 adjacent the stationary clamp plate 151.

Each of the passages 221 in the sprue base 165 communicates with aseparate L-shaped air passage 223 (one shown) in the piston shaft 167.The end of each of the separate L-shaped air passages 223 communicateswith a corresponding enlarged air passage 224 (one shown) in the forcebase 152. Each of the four enlarged air passages 224, which are plugged(not shown) at the outer surface of the force base 152, is larger thanthe communicating L-shaped passage 223 so that each of the L-shaped airpassages 223 remains in communication with the corresponding air passage224 when there is relative motion (about 0.003" to 0.005") therebetweenby movement of the piston shaft 167 with respect to the force base 152.

Each of the four enlarged air passages 224 communicates with acorresponding one of four equally angularly spaced air passages 225 inthe elongated hollow portion 180 of the force base 152. Each of the fourair passages 225 terminates at the angled surface 183 of the elongatedhollow portion 180 of the force base 152 to apply pressurized air to theangled surface 184 of the force cap 177.

The force of this pressurized air from the air passages 225 on theangled surface 184 of the force cap 177 causes relative motion of theforce cap 177, the piston shaft 167, the sprue base 165, the sprueheater shield 173, and the nozzle tip 170 with respect to the force base152. This slight motion of 0.003" to 0.005" allows pressurized air toescape between the angled surface 183 of the fixed force base 152 andthe angled surface 184 of the movable force cap 177. As a result, a thinlayer of pressurized air flows between the molded cylindrical wall 141of the container 142 and each of the elongated hollow portion 180 of theforce base 152 and the force cap 177 and between the molded end closure140 and the end surface 186 of the force cap 177. This strips the endclosure 140 and the integral cylindrical wall 141 of the container 142from the molding apparatus 150.

The molding apparatus 150 has O-rings 226 and 227 surrounding theannular chamber 222 and mounted in the sprue base 165. The slightrelative motion (0.003" to 0.005") between the sprue base 165 and thestationary clamp plate 151 does not result in the O-rings 226 and 227ceasing to engage the stationary clamp plate 151 because the O-rings 226and 227 are so compressed that they will remain sufficiently compressedto maintain a seal with the stationary clamp plate 151 even when thesprue base 165 is moved a slight distance therefrom. Therefore, there isno interruption of the flow of the pressurized air from the air line 220to the air passages 221 in the sprue base 165 when the sprue base 165 ismoved away from the stationary clamp plate 151.

The cavity plate 182 (see FIG. 19) has four equally angularly spacedgrooves 228 in its end surface 229. Each of the grooves 228 communicateswith a corresponding groove 230 in an angled surface 231 of the corering 153. The core ring 153 has four equally angularly spaced grooves232 with each in its end surface 233 communicating with a correspondingone of the four grooves 230 in the angled surface 231 of the core ring153. The end surface 233 of the core ring 153 engages the cavity ring211 when the molding apparatus 150 is in the positions of FIGS. 19-21.The grooves 228 (see FIG. 19), 230, and 232 cooperate to allow air toescape from the space between the elongated hollow portion 180 of theforce base 152 and the wall of the cavity 181 in the cavity plate 182when molten plastic flows thereinto.

The angled surface 231 of the core ring 153 is adjacent an angledsurface 234 of the cavity plate 182. The angled surfaces 231 and 234cooperate to insure precise alignment between the two portions of themolding apparatus 150 that are separated from each other to remove theend closure 140 (see FIG. 18) and the integral cylindrical wall 141 ofthe container 142 and then return when another of the end closures 140and the integral cylindrical wall 141 of the container 142 are to beformed.

The cavity plate 182 (see FIG. 19) has four equally angularly spacedgrooves 235 in its end surface 236, which is adjacent the water ring 191and the cavity retainer plate 209. The grooves 235 communicate withcorresponding grooves 237 in an end surface 238 of the cavity retainerplate 209 and an annular space 239 between the water ring 191 and thecavity retainer plate 209 to allow air to escape from the recess formedbetween the end surface 186 of the force cap 177 and the end surfaces190 and 194 of the core plug 187 and the handle post 193, respectively,when molten plastic is injected thereinto.

The stationary clamp plate 151 (see FIG. 22) has a dowel pin 240extending therefrom and disposed within a recess 241 in the sprue base165. This insures that the sprue base 165 remains properly aligned anddoes not shift from being advanced by the pressurized air or when beingretracted after the pressurized air is removed by molten plastic beingagain supplied through the orifice 185 in the force cap 177.

To form the single continuous score line 144 (see FIG. 17) of the endclosure 140, the end surface 186 (see FIG. 19) of the force cap 177 hasa projection 242 extending therefrom. This produces a relatively thinportion of the main panel 143 (see FIG. 17) of the end closure 140 tocreate the single continuous score line 144.

Coolant such as water is supplied to various portions of the moldingapparatus 150 (see FIG. 22). Coolant is supplied through a coolantconduit 244 in the force plate 154 and a communicating coolant conduit245 in the force base 152. The coolant conduit 245 communicates with aserpentine coolant channel 246, which is formed for approximately 180°between the piston shaft 167 and the force base 152.

Coolant is supplied from the coolant channel 246 to an annular coolantchannel 247 in the force cap 177 through a passage 248 in the pistonshaft 167. Coolant flows from the coolant channel 247 through a passage249 in the piston shaft 167 and diametrically disposed to the passage248. Coolant flows from the passage 249 through a serpentine coolantchannel 250, which is formed for approximately 180° between the pistonshaft 167 and the force base 152. The coolant in the coolant channel 250is returned to its source through a coolant conduit 251 in the forcebase 152 and a coolant conduit 252 in the force plate 154.

Coolant also is supplied to the cavity plate 182 (see FIG. 19) through aplurality of annular channels 255. Each of the annular coolant channels255 has a coolant supply conduit 256 in the cavity ring 211 connectedthereto and a coolant exhaust conduit 257 in the cavity ring 211connected thereto.

The movable core plug 187 also has coolant supplied thereto. Coolant iscirculated through an annular chamber 260, which is adjacent the waterring 191.

Coolant is supplied to the annular chamber 260 through a coolant conduit261 (see FIG. 23) in the movable core plug 187. The annular chamber 260is blocked by a coolant dam 262 adjacent the communication of theconduit 261 with the annular chamber 260. Thus, the coolant flows fromthe conduit 261 through the annular chamber 260 to one end of a passage263 in the core plug 187 since there is a coolant dam 264, which isdiametrically disposed to the coolant dam 262, in the annular chamber260 adjacent the communication of the annular chamber 260 with thepassage 263.

The passage 263 is slightly V-shaped so that it is lower at the centerthan at its ends. This insures that there is coolant adjacent theorifice 185 (see FIG. 19) in the force cap 177.

The passage 263 (see FIG. 23) has its other end communicate with theannular chamber 260 on the opposite side of the dam 262 from thecommunication with the coolant conduit 261. The coolant flows throughthe annular chamber 262 to a coolant conduit 265 in the movable coreplug 187 for return to its source. Each of the coolant conduits 261 and265 communicates through a coolant conduit (not shown) in the movablecore 189 (see FIG. 19) with the coolant source.

Coolant also is circulated in the interior of the handle post 193 (seeFIG. 20) through a blind bore 266 in the handle post 193. The bore 266has a divider baffle 267 therein to enable the flow of coolant waterthrough the bore 266 on one side of the baffle 267 and exhaust on theother side of the baffle 267 after passing beneath its end 268, which isspaced from the end of the bore 266.

Guide pins 270 (one shown in FIG. 20) are employed to provide properalignment of various parts of the molding apparatus 150. The guide pins270 are supported by the movable clamp plate 201.

While the single continuous score line 144 (see FIG. 17) has been shownand described as being spaced from the cylindrical wall 141 (see FIG.18), it should be understood that the single continuous score line 144(see FIG. 17) could be adjacent the junction of the main panel 143 andthe cylindrical wall 141 (see FIG. 18) if desired. The single continuousscore line 144 (see FIG. 17) would still be in the main panel 143, andthe opening into the container 142 (see FIG. 18) would be a maximum.

It should be understood that any of the other end closures having scoremeans could be utilized with the container 142 if desired. It would onlybe necessary to appropriately form cooperating parts of the moldingapparatus 150 to have the score means in the desired locations.

It should be understood that the molding apparatus 50 (see FIG. 7) isshown so that movement is in the vertical direction, but the desireddirection is horizontal to enable the formed end closure to fall bygravity after being stripped from the molding apparatus 50.

An advantage of this invention is that it is easy to remove an endclosure having a pull ring spaced from its main panel from its moldingapparatus without any damage thereto. Another advantage of thisinvention is that any end closure may be rapidly molded at a relativelylow cost. A further advantage of this invention is that an integralcontainer and end closure may be rapidly molded at a relatively lowcost.

For purposes of exemplification, particular embodiments of the inventionhave been shown and described according to the best presentunderstanding thereof. However, it will be apparent that changes andmodifications in the arrangement and construction of the parts thereofmay be resorted to without departing from the spirit and scope of theinvention.

We claim:
 1. A method of molding a one-piece end closure for closing anopen end of a container in which the end closure includes a main panelhaving at its periphery an annular surrounding portion, a pull ringdisposed in spaced and substantially parallel relation to the mainpanel, and means connecting the pull ring to the main panelincluding:injecting a molten plastic into a mold shaped to form the endclosure and including first mold means having molding surface means,second mold means having first and second molding surface means, andthird mold means having first and second molding surface means, thesecond mold means having passage means to receive a portion of the thirdmold means, the passage means in the second mold means having the secondmolding surface means of the second mold means and the portion of thethird mold means having the second molding surface means of the thirdmold means cooperating with the second molding surface means of thesecond mold means to form the pull ring when the portion of the thirdmold means is disposed within the passage means in the second mold meansso that the first molding surface means of the third mold means is inthe same plane as at least the portion of the first molding surfacemeans of the second mold means surrounding the first molding surfacemeans of the third mold means; disposing the portion of the third moldmeans within the passage means in the second mold means so that thefirst molding surface means of the third mold means is in the same planeas at least the portion of the first molding surface means of the secondmold means surrounding the first molding surface means of the third moldmeans prior to injecting the molten plastic to form the end closure;injecting the molten plastic between the molding surface means of thefirst mold means and the first molding surface means of each of thesecond mold means and the third mold means to form the main panel andthe annular surrounding portion of the first end closure; supplying themolten plastic from between the molding surface means of the first moldmeans and the first molding surface means of each of the second moldmeans and the third mold means to between the second molding surfacemeans of each of the second mold means and the third mold means throughcommunicating means in the second mold means with the connecting meansbeing formed by the molten plastic in the communicating means; producingrelative movement between the third mold means and the second mold meansto withdraw a portion of the third mold means from the passage means inthe second mold means prior to producing relative movement between thefirst mold means and the second and third mold means without shearing ofany molded material so that the pull ring is free to collapse prior tothe relative movement between the first mold means and the second andthird mold means to enable the pull ring to pass through the passagemeans in the second mold means when the formed end closure is disengagedfrom the first molding surface means of the second mold means; producingrelative movement between the first mold means and the second and thirdmold means substantially parallel to the direction of relative movementbetween the third mold means and the second mold means to disengage theformed end closure from one of the molding surface means of the firstmold means and the first molding surface means of the second mold meanswithout any shearing of the molded material; and disengaging the formedend closure from the other of the molding surface means of the firstmold means and the first molding surface means of the second mold means.2. The method according to claim 1 in which:the one of the moldingsurface means of the first mold means and the first molding surfacemeans of the second mold means is the molding surface means of the firstmold means and the other of the molding surface means of the first moldmeans and the first molding surface means of the second mold means isthe first molding surface means of the second mold means; anddisengaging the formed end closure from the first molding surface meansof the second mold means by moving fourth mold means relative to thesecond mold means substantially parallel to the direction of relativemovement between the third mold means and the second mold means todisengage the formed end closure from the second mold means.
 3. Themethod according to claim 2 including:producing the relative movementbetween the third mold means and the second mold means by moving thethird mold means relative to the second mold means; and producing therelative movement between the first mold means and the second and thirdmold means by moving the second and third mold means relative to thefirst mold means.
 4. The method according to claim 2 including formingscore line means in the main panel of the one-piece end closure byforming the main panel thinner where the score line means is to beformed through forming one of the molding surface means of the firstmold means and the first molding surface means of the second mold meanswith projecting means having the configuration of the score line means.5. The method according to claim 2 including forming score means in themain panel of the one-piece end closure by forming the main panelthinner where the score line means is to be formed through forming themolding surface means of the first mold means with projecting meanshaving the configuration of the score line means.
 6. The methodaccording to claim 1 in which:the one of the molding surface means ofthe first mold means and the first molding surface means of the secondmold means is the molding surface means of the first mold means and theother of the molding surface means of the first mold means and the firstmolding surface means of the second mold means is the first moldingsurface means of the second mold means; and disengaging the formed endclosure from the first molding surface means of the second mold means byapplying pressurized air to the formed end closure to disengage theformed end closure from the second mold means.
 7. The method accordingto claim 6 including forming score line means in the main panel of theone-piece end closure by forming the main panel thinner where the scoreline means is to be formed through forming one of the molding surfacemeans of the first mold means and the first molding surface means of thesecond mold means with projecting means having the configuration of thescore line means.
 8. The method according to claim 6 including formingscore line means in the main panel of the one-piece end closure byforming the main panel thinner where the score line means is to beformed through forming the molding surface means of the first mold meanswith projecting means having the configuration of the score line means.9. The method according to claim 1 including forming a wall of acontainer integral with the end closure by disposing wall mold meanshaving molding surface means in surrounding relation to portions of thefirst mold means and the second mold means to have the wall mold meansconstitute a portion of the mold into which the molten plastic isinjected.
 10. The method according to claim 9 including:producing therelative movement between the third mold means and the second mold meansby moving the third mold means relative to the second mold means; andproducing the relative movement between the first mold means and thesecond and third mold means by moving the second and third mold meansrelative to the first mold means.
 11. The method according to claim 9including forming score line means in the main panel of the one-pieceend closure by forming the main panel thinner where the score line meansis to be formed through forming one of the molding surface means of thefirst mold means and the first molding surface means of the second moldmeans with projecting means having the configuration of the score linemeans.
 12. The method according to claim 9 including forming score linemeans in the main panel of the one-piece end closure by forming the mainpanel thinner where the score line means is to be formed through formingthe molding surface means of the first mold means with projecting meanshaving the configuration of the score line means.
 13. The methodaccording to claim 1 including:producing the relative movement betweenthe third mold means and the second mold means by moving the third moldmeans relative to the second mold means; and producing the relativemovement between the first mold means and the second and third moldmeans by moving the second and third mold means relative to the firstmold means.
 14. The method according to claim 1 including forming scoreline means in the main panel of the one-piece end closure by forming themain panel thinner where the score line means is to be formed throughforming one of the molding surface means of the first mold means and thefirst molding surface means of the second mold means with projectingmeans having the configuration of the score line means.
 15. The methodaccording to claim 1 including forming score line means in the mainpanel of the one-piece end closure by forming the main panel thinerwhere the score line means is to be formed through forming the moldingsurface means of the first mold means with projecting means having theconfiguration of the score line means.